B5 Communicable Diseases Flashcards
what is a communicable disease?
a disease which can be spread from person to person
how are communicable diseases spread?
by pathogens such as bacteria or viruses
how do different diseases interact with each other?
one disease can put someone at risk of other diseases
one disease can also cause another
what are pathogens?
microorganisms which cause infectious disease
what are some examples of pathogens?
bacteria
viruses
protists
fungi
how do bacteria make humans ill?
once inside the body, they reproduce rapidly
they can then release harmful chemicals (toxins)
toxins damage tissues and make us feel ill
how do viruses make humans ill?
the virus invades the host cell
it then reproduces inside the cell
this is very damaging to the cell and cause it to burst open and die when the virus leaves
how do viruses reproduce?
they have to use a host cell
how are pathogens spread?
in the air (e.g. water droplets)
directly in water
direct contact by individuals
how can the spread of pathogens be reduced?
washing hands before eating
clean drinking water
isolation
vaccination
what type of pathogen is malaria?
a protist
what is the life cycle of the malaria pathogen?
an infected person is bitten by a mosquito. the pathogen passes into the mosquito.
the mosquito then bites a different person and infects them
what is a vector?
another organism which carries a pathogen from one person to another without being infected itself
what are the mains ways to stop the spread of malaria?
stop the vector from breeding - drain areas of still water, spray areas with insecticide
prevent mosquitoes biting humans - sleep under mosquito nets
give 2 examples of viral diseases:
measles
HIV
can antibiotics kill viruses?
no.
viruses cannot be killed by antibiotics
what are the symptoms of measles?
high fever
red skin rash
how is measles spread?
in droplets when an infected person coughs or sneezes
the virus then passes to a different person when the droplets are inhaled
what can happen if someone has measles?
complications can develop
this can cause damage to the breathing system and the brain
it can also be fatal
what are young children given to protect them against measles?
a vaccination